High iron by itself is unusual in my buses. Usually you have corresponding increases in chrome if its a cylinder problem and oftentimes an increase in silicon/dirt as well if an intake hose is disconnected or chaffed through, or an air filter has a hole torn in it. I don't have any VT's but I've got a ton of MF7's and that kind of iron is about 10X what I would expect. Do you remember anything unusual on the magnet? You might consider cutting open the oil filter if it's still around, and looking in the pleats.

Runs good, no filter (threw it away, never thought a thing about it). Sodium is 5 and I don't have potassium listed. Chrome is 1. I did not remember anything other than very fine particles on the magnet. I will be bringing this in at some point and checking the turbo and power steering gear (thanks to Jim at Mid-West Transit for that tidbit of information). I guess if it's the cam that's going to be a major tear down. Argggh!!

I am basing the change intervals the way man kind has changed oil since the beginning of time, mileage. lol I don't know how that would figure out. I guess a little like this; I'm changing at 8k with synthetic. So I am guessing if you average 25 to 30 mph on a route it would come out to about 8,750 to 10,500 miles on the hours. So that would be a yes. As for 6 months, that would be a positive and the 1,000 gallon thing would vary I guess. I think I'm getting about 7mpg so I'd be going a little over on that. Boy, why do engineers feel the need to make things out of this world complicated? You think I need to change more often? This kind of proves my point on propane doesn't it?

Sounded like you might have been extending drain intervals because of synthetic oil and oil analysis. Regardless, once wear metals start showing up in a HEUI engine the problem can snowball because there is so much oil that never drains out during an oil change. On a VT365 it is close to one gallon of oil or around 20% of the lube oil circulating through the engine immediately after an oil change is old oil.

Sounded like you might have been extending drain intervals because of synthetic oil and oil analysis. Regardless, once wear metals start showing up in a HEUI engine the problem can snowball because there is so much oil that never drains out during an oil change. On a VT365 it is close to one gallon of oil or around 20% of the lube oil circulating through the engine immediately after an oil change is old oil.

What are your suggestions? I plan to get this in soon. We have been off because of weather since I discovered this.

I am always trying to learn new things (one reason I frequent this site). I am using a NAPA 7312. Reckon that has a Racor patent number? If I find the P/S gear or turbo to be the problem I will probably not increase the frequency unless my dealer says it's advisable. But if it's an internal engine problem I probably won't have the chance to change the oil again anyway. Time will tell.

I don't try to keep up with what the aftermarket filter people put in their boxes. I always use 1840752C91 International filters from the dealer for this application. I do have 190,000 miles on one of these engines with the turbo being the only non original part.

I don't try to keep up with what the aftermarket filter people put in their boxes. I always use 1840752C91 International filters from the dealer for this application. I do have 190,000 miles on one of these engines with the turbo being the only non original part.

Never had any trouble with NAPA filters so I don't plan to change. Just wondering if you think the Navistar filter has an advantage over NAPA (WIX) and why.

I only use International filters too. And always use Allison filters for my transmissions.I also don't do oil analysis and change my oil every 450 hrs.Some routes this will be 6,000 miles while on others it could be 9,000 hrs.

I don't try to keep up with what the aftermarket filter people put in their boxes. I always use 1840752C91 International filters from the dealer for this application. I do have 190,000 miles on one of these engines with the turbo being the only non original part.

Never had any trouble with NAPA filters so I don't plan to change. Just wondering if you think the Navistar filter has an advantage over NAPA (WIX) and why.

The filter housing is made by Racor and is patented, in the past, companies making replacement elements to fit this housing have made changes from Racor's design in order to avoid patent infringement. Some of these "will fit" elements have been implicated as not providing proper fit and function within the housing. I prefer not to risk it myself, especially on this engine. In other words, brand X filter in a brand X can = ok, brand Y filter in a brand X can, maybe not for me.

I wonder why they use the cartridge type filter when clean oil is so important to these engines. It loooks to me like a lot of dirty oil falls back into the oil filter housing when you change it

When the lid is unscrewed from the canister the element raises up and and opens a valve which allows the oil to drain into the pan, very important on these engines to change the filter while warm and before drain plug is replaced in pan. Some "will fit" elements in the past have been implicated in allowing oil drain back to the pan without unscrewing the filter cap, which would in effect bypass the oil filter during engine operation. One reason why I like to take no risks and look for the Racor patent numbers and felt seal ring on my filters for this application. And I would not care if the box is NAPA or the house brand from Mega Lo Mart as long as the element inside has the Racor patent numbers on it.

OK, I am seeing oil standing in bottom of the tubing when I took the rubber/ plastic tubing off leading from the air filter to the turbo. Blow by?

We are dealing with the same problem this week. Ours is so bad oil is dripping out of the CAC tubes. We have eliminated the air compressor and we have a lot of blow by. I think blow by is the culprit but we replaced crankcase breather today and hope that helps. I'm sure there will be piston rings coming shortly if this doesn't help.

Well the crankcase breather changed nothing, so my guys pulled the heads and a piston and found the compression rings are VERY pitted.The cylinder wall still has the cross hatching and a couple scars in it. I'm guessing the multiple EGR failures? Could the compression rings pitting and scarring the cylinder walls be where the Fe in your samples are coming from???

Yes we do oil samples at 5k intervals. But I looked at this particular bus history today and it hasn't had any abnormal iron levels. The highest level was 116 and that was 2 years ago and has since dropped to 79 on the last sample. Hope you figure it out before you have a major failure.

Yes we do oil samples at 5k intervals. But I looked at this particular bus history today and it hasn't had any abnormal iron levels. The highest level was 116 and that was 2 years ago and has since dropped to 79 on the last sample. Hope you figure it out before you have a major failure.

Yeah, me too. I've got an older Chevy with a Cat engine giving me trouble now. Never ends with an old fleet.